public class Main {
    public static void main(String[] args) {
        // 现有欧洲电源
        EuropeanSocket europeanSocket = new EuropeanSocket();

        // 创建适配器，转换为5V
        FiveVolt adapter = new VoltageAdapter(europeanSocket);

        // 客户端使用统一接口
        System.out.println("输出电压: " + adapter.getVolt5() + "V"); // 输出: 5V
    }
}
